Germination is a mechanism

The germination is the process by which a seed develops into a new plant . This process takes place when the embryo is inflated and the seed coat is broken. To accomplish this, each new plant requires basic elements for its development: temperature , water , oxygen and mineral salts . The most common example of germination is an outbreak of a seed from a seed of a plant or floral angiosperm . However, the growth of a hypha from a sporefungal germination is also considered. In a more general sense, germination can imply anything that expands into a larger being from a small existence or germ . Germination is a mechanism of sexual reproduction of plants.

The seed develops from a anterozoide located inside the pollen tube of a flower . It reaches the ovary entering the micropyle to the egg , which produces the fertilization . Subsequently, the egg becomes seed ovary and pericarp or fruit . In seed development is characterized by three states to have occurred after the pollination :

Germination is called the process by which embryonic growth resumed after the resting phase. This phenomenon is not triggered until the seed has been transported to a favorable environment for the agents of dispersal. The determining conditions of the medium are: Provide adequate water , oxygen , and temperature appropriate. Each species prefers a certain temperature to germinate, in general, extreme cold or heat are not conducive to germination but the exhumation of bodies to sprout in different parts of bodies increasingly extended to the Middle East in which farmers leave their crops and will return to modern irrigation. Some seeds need to go through a period of dormancy and, thereafter, also a fixed period of exposure to light to initiate germination.

During germination, water diffuses through the jacket of the seed and reaches the embryo , that during the resting phase is dried almost completely. The water causes the seed to swell, sometimes to the point of tearing the outer sheath. Several enzymes break down the nutrients stored in the endosperm or the cotyledons into simpler substances that are transported through the interior of the embryo to the growth centers. The oxygen absorbed allows the seed to extract the energy contained in these sugars reserve, so you can start the growth .

The radicle is the first spring element embryonic through the seed coat. Form root hairs that absorb water and subjected the embryo to the ground. Then begins to elongate the hypocotyl, which pushes the plumule, and in many cases the cotyledon or cotyledons, towards the soil surface.

Cotyledons light emerging form chlorophyll and carry out photosynthesis until they develop the sheets from the true plumule. In some species, especially grasses , the cotyledons never reach the soil surface, and photosynthesis does not begin until the true leaves develop, in the meantime, the plant remains at the expense of nutrient reserves stored in the seed. From the beginning of germination until the plant achieved full independence of the nutrients stored in the seed, the plant is called a seedling.